Oil Change-Message Center

[DMAX_Phil]

I searched but couldn't find anything on this subject. Anyone know how the oil change monitor works. The manual says it monitors engine revs, hours, etc. but the first time I ever saw this message was today at 20K miles. The manual says it does not detect dust/dirt in the oil and I have a hard time beleiving they have any type of viscosity measurement in the monitor. Seems like it is just a timer that counts an algorithm of hours, revs, temp. extremes (?), mileage (?).

I'm baffled because it seems the monitor would have first gone off at around 5-7K miles and not 20K. I have never reset the "change oil" message before today. All this time I just thought that since I change the oil every 3,500 that the monitor detected new oil and that is why it did not go off but now I'm not sure about this.

Any insight? Thanks.


Phil

[DmaxMaverick]

The 01's are only by mileage. Mine goes off at exactly 5K, just like clock work, 11 times now. Not sure about the 02/03 Duramax. The gassers set the indicator like you describe.

If you have a juice box, the programming procedure will reset the oil indicator.

Other than that, someone else must have reset it for you. Many of the oil changer places do it without telling you. Depends on where you get your oil changed. If you change your own oil, and don't have juice, who knows? Maybe it was broke and healed itself???

[IndigoDually]

I haven't waited for the message to come on before I change my oil. I haven't reset it at each change because I wanted to see how long it said my intervals should be. It lights at around 8800 mi for me and I don't go any longer than about 3500-4000 mi on Amsoil Synthetic. I did go 250 hours once but I feel that was a little longer than I wanted.
I try to change the oil at 3-4k depending on the oil. I use synthetic in the winter and stretch the intervals and run dino in the warmer months and shorten them.

John

[ 03-24-2003: Message edited by: IndigoDually ]</p>

[ram/tx]

I don't know how the oil change monitor works, but I had a 99 gasser and it went off at about 6,400 miles and my 01 DMax will go off at about 7,800 miles. Didn't reset one oil change just to see what mileage it would go off. Have 6,000 miles on the oil now and no message to change the oil. I normally change it at 5,000 miles, but this time other things have gotten in the way and just haven't had the time, will do it this week.

[Searay90]

My 02 didn't go off until I hit 8,500 miles. I had already done 3 oil changes by the time the light came on for the first time. I went about 6K miles on my last oil change (about 3K of straight Hwy driving), and the oil life monitor still had 23.5% remaining on it. I use an autotap set up and my laptop to see the actual value in the PCM.

[Kennedy]

I have a buddy with an 8.1 that I service. When I do his reset, I use the Tech 2 and set him to 80% to make sure it goes on plenty early...

FWIW, the Juice will now switch levels with 2 pumps on the pedal.

[DMAX_Phil]

Okay, so it sounds like the DMAX isn't simply by mileage, otherwise everyone's should go off at the same time. I have performed all but two of my oil changes. The guys at the lube shop must have reset the monitor on these two visits.

I was kind of worried my DMAX was telling me that I was driving like an old lady...


Thanks,

Phil

[a64pilot]

The 01 is definately on mileage. early ones at 5000 I think and later ones and PCM reflashed ones at 7500. I believe that the 03 ones run an algorythem like the gas vehicles. # of cold starts, rpm, hours etc.
FWIW the GM cars are calibrated for Dino oil, except the Vette which is calibrated for syn. For this reason I use syn in the wifes 02 SS Camaro and change oil when the message comes on.
If the 03's use an algorythem it would be more accurate to use the reminder to change your oil.
I.E. change your oil when 50% of your oil life remains etc.

[hjd3021]

Searay90,

I note that you were using the Autotap on a laptop to look at this parameter. How many parameters do you see on your setup. I'm using the enhanced setup on the same truck and see only about 60 or so. It finds the VIN number automatically so I think it is working correctly but I'm not sure that it is seeing all there is to see.